A general process for producing a turbine or compressor blade having a plurality of passages therein relatively close to the surface for passage of fluid therethrough for cooling the blade is set forth in U.S. Pat. No. 2,641,439 -- Williams. The Williams patent is incorporated by reference.
The Williams patent provides that in forming a turbine blade the surface of the core has formed therein a plurality of grooves separated by ridges. Cover for these grooves to define passages for the conduct of cooling fluid during use is provided by plating a layer of metal over the bucket core, the grooves first being filled with a material such as aluminum, cadmium or a graphite-containing wax. Thereafter, one or more layers of metal are deposited thereover by electrodeposition forming the skin. The skin having been deposited and bonded in place, the patent describes the removal of the filler material to leave open passages defined by the grooves and the metal skin deposited thereover.
The art is in constant need of easier and more economical techniques for the application of skin over bucket cores of compound curvature to provide cooling passages. It is to this problem that the instant invention is directed.